A humorous blokey northern English exclamation.
Spoken ironically when delivering an unwanted gift or gesture, such as when throwing a drinking partner's coat at his head when it's time to move pubs, or cutting up other vehicles in traffic.
Always intended to raise a laugh.

Originally heard outside Manchester in a UK TV beer ad, where a comedian called Peter Kay joins in a fancy-footwork soccer practice but kicks the ball very hard and scores, shouting 'Ave iiiiiiiiiit!!'